Telephone-transmitter.



No. 632,355. Patented Sept. 5, I899.

T. LIDBERG.

TELEPHONE TRANSMITTER.

(Application filed Dec. 27, 1898.)

(No Model.)

FIG. 1.

WITNESSES I J I/I/ 05% IN VE N 70/? A TTOHNEY.

' means of screws b.

TIODOLF LIDBERG, OF CHICAGO, ILLINOIS, ASSIGNOR OF ONE-HALF TO HAL H. DAVENPORT, OF SAME PLACE.

TELEPHONE-TRANSMITTER.

SPECIFICATION forming part of Letters Patent No. 632,355, dated September 5, 1899.

Application filed December 27, 1898. Serial No. 700,466. (No model.)

To all whom, it may concern:

Be it known that I, TIODOLF LIDBERG,a citizen of the United States, residing in Chicago, in the county of Cook and State of Illinois, have invented a new and useful Improvement in Telephone-Transmitters, of which the followingis a specification.

My invention relates to improvements in telephone transmitters, the object of which is to increase the sensibility and effect of the diaphragm.

Heretofore the diaphragms of transmitters have been constructed to move bodily against the pressure of an auxiliary spring, the said diaphragms being usually secured to the transmitter-case at a point opposite to the spring, with reference to the diameter of the diaphragm, and moving as if pivoted at the point where it is thus secured, as in the wellknown Blake transmitter type, or the diaphragms have been uniformly secured around the surface of the circumference, and the resilience of the diaphragm only has been depended upon for the vibratory responses. I have found the operation of both classes of diaphragms to be sluggish and inactive in comparison to my new improved device.

To this end my improved transmitter consists of a case with a diaphragm uniformly and securely held around the periphery, between the said case and the cap thereof, and two or more auxiliary springsresting upon the inside surface of the diaphragm and exerting an outward pressure against the said diaphragm, the object of which is to hold the diaphragm in a state of stress between its outside circumference and the center thereof, all of which is plainly shown in the accompanying drawings, which form a part hereof, in which Figure 1 is a sectionalview ofmy complete transmitter. Fig. .2 is a plan View of the same with the outside cap broken away, showing the diaphragm, and the diaphragm also broken away, showing one of the springs.

Like letters of reference refer to similar parts.

In Fig. 1, a is an ordinary transmitter-retaining case. b is a cap adapted to fit over the enlarged end and is attached thereto by The diaphragm c is securely held around the edge of its periphery between the transmitter-case and cap. Springs (1 d are secured to the inside of the case a and are made to bear with considerable pressure against the inside surface of the diaphragm of the screw a which passes through the in sulating-block a and the washer a, all of which is held in place by means of nut a Granulated carbon a is contained in the space between the two carbon buttons at and 0 A piece of felt or like material for retaining the granulated carbon in place may be carried by either of the carbon buttons.

The electric terminals of my transmitter are the nut c and the case a.

My improvement may be applied to a receiver or to any type of transmitter in which a diaphragm is used.

Having described my invention, What I claim as new, and desire to secure by Letters Patent, is

1. In a telephone transmitter or receiver, a diaphragm a part thereof lying in a normal plane, another part thereof, under stress, in a plane removed therefrom but parallel therewith, substantially as set forth.

2. In a telephone receiver or transmitter,

the combination of a diaphragm, a clamp around its circumference for securing it bodily in position, two or more springs in opposite zones incontact with the said diaphragm between the center and the circumferential bearing thereof, said springs being adapted to exert an outward pressure whereby said diaphragm is displaced in a plane parallel with its normal plane, substantially as set forth.

In testimony whereof I have signed this specification, in the presence of two subscribing witnesses, this 12th day of December,1898.

TIODOLF LIDBERG.

W'itnesses:

HAL H. DAVENPORT, M. F. ALLEN. 

